The Federal Trade Commission cleared Facebook’s $19 billion acquisition of messaging service WhatsApp, but the approval came with a caveat.

The FTC’s Bureau of Consumer Protection notified Facebook and WhatsApp that both companies will be subject to Facebook’s 2012 agreement with the FTC, which required Facebook to give consumers notice and obtain consent before sharing information beyond their privacy settings, and to maintain a privacy program to protect consumers’ information.

If WhatsApp doesn’t honor the agreement, “both companies could be in violation” of the law and the agreement, the bureau said in a letter.

A Facebook spokeswoman said in a statement the company is “pleased the FTC has completed its review and cleared our acquisition of WhatsApp,” but declined to comment on the FTC’s privacy concerns.